SB2026071041 - Multiple vulnerabilities in CoreDNS



SB2026071041 - Multiple vulnerabilities in CoreDNS

Published: July 10, 2026 Updated: July 13, 2026

Security Bulletin ID SB2026071041
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 67% Low 33%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 vulnerabilities.


1) NULL pointer dereference (CVE-ID: N/A)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error within 28-byte UDP datagram when the proxyproto plugin is enabled. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.


2) Uncaught Exception (CVE-ID: N/A)

CWE-ID: CWE-248 - Uncaught Exception

CVSSv4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to uncaught exception within k8s_external. A remote attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.


3) NULL pointer dereference (CVE-ID: N/A)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a null pointer dereference in the rewrite plugin edns0 response-revert rules when processing a downstream response with no OPT record after a matching edns0 rewrite rule with the revert flag enabled. A remote attacker can send a DNS query that triggers the queued response rule to cause a denial of service.

If the debug directive is enabled, the panic is not recovered and the issue can crash the entire CoreDNS process.


Remediation

Install update from vendor's website.